I did not go to a 9.3 for a few reasons . First of all from other projects I had read about the 9.3 would need the magazine and feeding ramp altered . With the .338 this was not necessary . Headspace is exactly the same as a .303 : just a matter of re boring the barrel to 338 .Secondly I wanted to use .303 neck sizing die with a 338 expander ball for reloading. The 338 expander plug fit perfectly with no neck collet in the .303 die . Perfect . A 9.3 /303 would have needed an entire set of custom dies . The choice of 338 bullets is 100 times greater than the 9.3 choices . I have tailored loads to perfectly fit my Cape sights with the 338/303 Nitro Express .